Employee information table employee: user_id, name, store_id, salary
Store Table stores: store_id, name, city
参考答案:select a.city from stores a,employee b where b.store_id=a.store_id group by b.store_id having avg(b.salary)<5000
Employee information table employee: user_id, name, store_id, salary
Store Table stores: store_id, name, city
参考答案:select a.city from stores a,employee b where b.store_id=a.store_id group by b.store_id having avg(b.salary)<5000